Weight measurements of liquids in flexible containers

Abstract

Articles and methods for measuring weight of a liquid in a disposable bag bioreactor are presented. In certain embodiments, bioreactor systems described herein include a supported container (e.g., a flexible bag in a reusable housing) for containing a liquid, and at least two pressure indicating sensors operatively associated with the container. A first pressure indicating sensor can be placed near the bottom of the container to measure the total downward force within the container, including the liquid head in the container and the gas pressure above the liquid. The second pressure indicating sensor can be placed near the top of the container to measure only the pressure at the top of or above the liquid. Signals from the pressure indicating sensors can be directed to a control system that receives the signals and calculates a difference between the signals. This difference can be used to determine a volume or a weight of the liquid in the container. Advantageously, real-time weight measurements can be obtained while the system is in operation and continuous flow processes can be monitored. Moreover, in some embodiments, the pressure indicating sensors are isolated from contact with any fluid (e.g., liquid) in the container and, therefore, do not require cleaning after processing of each batch of reactants. Contamination of the process fluid by contact with the pressure indicating sensors can also be avoided.

Description

RELATED APPLICATIONS[0001]This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 60 / 903,977, filed Feb. 28, 2007, entitled “Weight Measurements of Liquids in Flexible Containers”, which is incorporated herein by reference in its entirety.FIELD OF INVENTION[0002]The present invention relates generally to flexible containers, and more specifically, to systems and methods for measuring weight of a liquid contained in a flexible container, such as a disposable bag, supported by a reusable support structure. The flexible containers may be used as bioreactors for performing chemical and / or biological reactions contained therein.BACKGROUND[0003]Systems and techniques for determining the weight and / or volume of liquid contained in bioreactors including flexible containers, such as disposable bags contained in reusable support structures, have been designed to include pressure indicating sensors for measuring weight and / or volume of a liquid in the...

AI Technical Summary

Benefits of technology

[0005]In one aspect of the invention, a series of bioreactor systems are provided. In one embodiment, a bioreactor system comprises a flexible container for housing a liquid in the container and a reusable support structure for surrounding and containing the flexible container. The bioreactor system also includes a first pressure or force indicating sensor operatively associated with the flexible container but not in fluid contact with any fluid in the flexible container, the pressure or force indicating sensor configured to measure a parameter indicative of a first pressure in the flexible container. The bioreactor system also includes a second pressure or force indicating sensor operatively associated with the flexible container, the pressure or force indicating sensor configured to measure a parameter indicative of a second pressure in the flexible container. A control system may be configured to receive input from the first and second pressure or force indicating sensors indicative of the first and second pressures and to calculate a difference between the first and second pressures.

[0006]In another embodiment, a bioreactor system comprises a flexible container for housing a liquid in the container and a reusable support structure for surrounding and containing the flexible container. The bioreactor system may also include a first pressure or force indicating sensor operatively associated with the flexible container and configured to measure a parameter indicative of a first pressure in the flexible container and a second pressure or force indicating sensor operatively associated with the flexible container and configured to measure a parameter indicative of a second pressure in the flexible container. The bioreactor system may also include a control system configured to receive input from the first and second pressure or force indicating sensors indicative of the first and second pressures and to calculate a difference between the first and second pressures.

[0007]In another embodiment, a bioreactor system comprises a flexible container for housing a liquid in the container, at least one pressure or force indicating sensor operatively associated with the flexible container but not in contact with any fluid in the flexible container, the pressure or force indicating sensor configured to measure a parameter indicative of a pressure in the flexible container. The bioreactor system may also include a control system configured to receive input from the at least one pressure or force indicating sensor indicative of the pressure, the control system configured to determine from the input a volume or a weight of a liquid in the flexible container.

[0008]Other advantages and novel features of the present invention will become apparent from the following detailed description of various non-limiting embodiments of the invention when considered in conjunction with the accompanying figures. In cases where the present specification and a document incorporated by reference include conflicting and / or inconsistent disclosure, the present specification shall control. If two or more documents incorporated by reference include conflicting and / or inconsistent disclosure with respect to each other, then the document having the later effective date shall control.

Problems solved by technology

The former systems have disadvantages of requiring cumbersome, large and often costly scales and to being susceptible to vibration and shock.

The later systems suffer from being inaccurate for applications where there may be a gas phase present in the flexible container at greater than atmospheric pressure and from having the potential to introduce contamination into the process fluid.

However such systems are not well suited for measuring weight and / or volume of a liquid in a flexible container, such as a disposable bag.

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